To design a reasonable structure of cathode with high electrical conductivity is important for the development of the lithium-sulfur batteries. Less electronic conductivity of cathode will lead to the poor rate capability. In this paper, we constructed the Li₂S-P₂S₅ system as the composite cathode model of the lithium-sulfur battery and used first-principles calculations to study P₂S₅-adsorbed Li₂S(110) surface, including surface's structural stability, absorption type, and electronic properties. It is found that P₂S₅ is strongly adsorbed on the Li₂S(110) surface with the adsorption energy -7.16 eV per molecule. Our calculations reveal the micro mechanism why the Li₂S-P₂S₅ is a high-performance composite cathode material: appearance of new electronic states and the formation of two PS₄³⁻ from per P₂S₅ molecule.

设计具有高电导率的阴极的合理结构对于锂硫电池的开发很重要。阴极的电子电导率较低将导致差速能力。在本文中，我们构建了Li ₂ S-P ₂ S ₅体系作为锂硫电池的复合阴极模型，并使用第一性原理计算来研究P ₂ S ₅吸附的Li ₂ S（110）表面，包括表面结构稳定性，吸收类型和电子特性。发现P ₂ S ₅强烈吸附在Li _2上S（110）表面，每个分子的吸附能为-7.16 eV。我们的计算揭示了Li ₂ S-P ₂ S ₅是高性能复合阴极材料的微观机理：出现新的电子态并从每个P ₂ S ₅分子形成两个PS ₄ ^3-。